1. Field of the Invention
The present invention relates generally to a system, method and apparatus for filling a container. More specifically, the present invention relates to a system, method and apparatus for vacuum-assisted filling of medicinal capsules with a precise dosage of dry powder pharmaceutical.
2. Related Art
In medicine, it is often desirable to administer various forms of medication to patients. A well known method of introducing medication into the human body is the oral ingestion of capsules. In another method, a patient may inhale certain medications through the nose or mouth. Inhalable medications come in numerous forms, including solids that are typically in the form of fine, dry powders. Specialized devices, such as inhalers, are typically provided to assist the patient in directing these fine powder medications through an airway and eventually into the lower respiratory tract. Various means for loading an inhaler with a proper dose of medication prior to use are known, including the use of capsules. For example, U.S. Pat. No. 5,787,881 discloses an inhaler that is used with encapsulated dry powder medicaments. Such devices require that capsules containing precise doses of medicament be available. The capsules are punctured and then inserted into the inhaler for inhalation of the medicament contained therein.
Countless other applications as well rely upon containers containing a specified amount of any of a number of materials. Many devices are known for filling such containers. However, each of these devices suffers certain drawbacks. U.S. Pat. No. 5,743,069, for example, discloses a metering device for medical applications. In this device, metering members are used to mechanically meter dosages of pharmaceutical through a plurality of holes, and eventually into a plurality of capsules. However, such mechanical metering devices, which rely only on mechanical members and gravity to apportion a particular dose of powder from a larger supply thereof, may lead to inaccurate doses. Such inaccuracies can result from, among other things, air pockets or clumps of powder in the supply. In addition, medical applications relating to inhalable medicaments may involve the handling of very fine, low-density powders. It has been found that these powders are difficult to handle due to their tendency to aerosolize, or become airborne, at the slightest provocation. Thus, a device for the metering of such powders must be designed with this quality in mind.
U.S. Pat. No. 5,826,633 discloses a powder filling apparatus for transferring an amount of powder to a receptacle. While the device addresses a problem of conglomerated powder through the use of a fluidizing means, the device is rather complex. Included are a variety of mechanical parts having relatively complicated interactions, and two motors requiring an external power supply. In addition, sources of vacuum and/or pressure are required.
Other devices, such as that disclosed in U.S. Pat. No. 5,809,744, address a problem of preventing aerosolization of fine powders, also through application of a vacuum. However, the device of U.S. Pat. No. 5,809,744 draws a vacuum directly through a container, such as a filter bag, into which a material such as coffee is to be vacuum-packed. Because such a device utilizes a vacuum for packing, it is not readily suitable for metering an accurate amount of a material for delivery to a non-porous container. Such a device cannot fill containers such as medicinal capsules, through which a vacuum is not easily drawn. In addition, medical applications regularly require high accuracy on a far smaller scale of dosage than the disclosed larger-scale device could offer.
Still other devices, such as the material apportioning apparatus disclosed in U.S. Pat. No. 4,671,430 and the powder filler disclosed in U.S. Pat. No. 4,949,766, attempt to overcome the above problem by apportioning material in a different container from that which is intended to eventually contain the apportioned amount. However, such devices fail to provide the simplicity of design and ease of use sought by those in the art.
Other conventional capsule filling machines have other disadvantages. Typically such conventional machines are designed to pack large amounts of powders into capsules, and are not optimal for delicate porous powders. Additionally, such conventional machines require a large volume of powder (e.g., greater than 500 ml) to prime the machine. Consequently, for some protein powders, in excess of $100,000 worth of powder is wasted just to prime the machine to fill one capsule.
Thus, there is a need in the art for an improved method and apparatus for filling containers with a precise dosage of dry powder. Specifically, what is needed is a method and apparatus capable of consistently delivering a precisely metered dose of dry powder medicament to a capsule. Preferably, such a device would further be simple in design and easy to use, through either manual or computer-controlled operation. The device would also be adapted to handle the low-density fine powders often present in medical applications, and to vacuum pack such powders into relatively small and highly accurate doses for delivery to a container, using a small priming volume. The present invention, the description of which is fully set forth below, solves the need in the art for such an improved method and apparatus.
The present invention relates to a system, method and apparatus for filling containers. In one aspect of the invention, an apparatus for filling containers with powder is provided. The apparatus includes a powder hopper for dispensing powder, a dosing plate and a dosing wheel. The dosing plate has a dosing hole, and is movable between first and second positions. The dosing wheel includes a container receptacle for holding a container to be filled. The apparatus also includes an ejector member. When the dosing plate is in the first position, the dosing hole is positioned to receive a dose of powder dispensed from the powder hopper. When the dosing plate is in the second position, the dosing hole is positioned so that actuation of the ejector member ejects the dose into the container receptacle.
In another aspect of the present invention, a method of filling a container with powder is provided. One aspect of the method involves placing a container in a container receptacle defined by a dosing wheel. The method involves dispensing a dose of powder into a dosing hole defined by a dosing plate when the dosing plate is in a first position, the dosing plate being movable from the first position to a second position. The method also involves moving the dosing plate to the second position such that the dosing hole is in registry with the container in the container receptacle. Finally, the method involves actuating an ejector member to eject the dose of powder from the dosing hole into the container.
In still yet another aspect of the present invention, another method of filling a container with powder is provided. This method involves placing a container in a container receptacle defined by a dosing wheel when the dosing wheel is in a first position, the dosing wheel being movable from the first position to a second position. The method further involves dispensing a dose of powder into a dosing hole defined by a dosing plate when the dosing plate is in a first dosing plate position, the dosing plate being movably coupled with the dosing wheel and being movable from the first dosing plate position to a second dosing plate position. The method also involves rotating the dosing wheel such that the container receptacle is in the second position and thereby causing the dosing plate to move to the second dosing plate position with the dosing hole in registry with the container receptacle, and actuating an ejector member to eject the dose of powder from the dosing hole into the container.
In yet another aspect, a system for filling containers with powder is provided. The system includes a carousel. Disposed in the carousel is a container handling mechanism that includes a container block defining a container receptacle and a cap carrier defining a cap receptacle. The cap carrier is movable between a first carrier position and a second carrier position. The system further includes, adjacent the carousel, a dosing portion having a dosing plate defining a dosing hole. The dosing plate is movable between a first dosing position and a second dosing position, such that when the dosing plate is in the first dosing position, the dosing hole is positioned to receive a dose of powder. When the dosing plate is in the second dosing position, the dosing hole is positioned to dispense the dose of powder into the container receptacle.
Features and Advantages
One feature of the present invention is that it is well adapted for use with a variety of materials, including the very fine, low-density powders typically found in applications relating to inhalable medicaments.
Another advantageous feature of the present invention is that it is relatively simple in design and easy to use. Therefore, the device can be produced less expensively than more complex devices, and only very limited training is required prior to use.
The present invention also possesses the advantage that it consistently provides a high accuracy dosage of material to a container, as is important to a great number of applications. Further, the present invention requires a very small amount of powder for priming, typically less than 500 mg of powder.
Because the present invention carries the additional advantage that it can be manually operated, it can be readied for a single use in a short period of time. This renders it ideal for a laboratory environment where dosages are often required quickly and in limited quantities.
The present invention also advantageously can be computer-controlled and adapted for use in large-scale commercial filling facilities.
Further features and advantages will become apparent following review of the detailed description set forth below.